As someone who has spent decades watching fuel move through pipelines, terminals, and the long chain of businesses downstream of them, I have learned to distrust any inflation story that treats energy as a footnote. For most of this spring, energy was not a footnote. It was the headline, the subhead, and most of the body copy too. And then, almost overnight, the story flipped. If you want to understand why the people who set interest rates suddenly look a little more relaxed, do not start with the central bank. Start with a barrel of crude and a narrow stretch of water between Iran and Oman.
Here is my thesis, and I will defend it below: the swing variable in this year’s inflation fight was never the policy rate. It was the price of oil. The Federal Reserve has new leadership and a new communication style, but the thing that actually changed the inflation outlook in June was physical, not monetary. Barrels started moving again.
The Spring the Barrel Ran the Economy
Cast your mind back a few weeks. By May, headline inflation had climbed to 4.2% year over year, its highest reading in three years. When you open the hood on that number, the engine is obvious. Energy prices jumped 3.9% in a single month and were up more than 23% over the year. Gasoline alone rose 7% in May and sat about 40% above where it started the year. By one accounting, energy was responsible for over 60% of the entire monthly increase in consumer prices. Core inflation, the measure that strips out food and energy, was actually well behaved, rising just 0.2% on the month. In plain terms, the economy did not have a broad inflation problem. It had an oil problem wearing an inflation costume.
This is the part that gets lost in the macro commentary. When a chemical engineer looks at a 4.2% print driven by energy, the question is not “what will the central bank do.” The question is “what is happening to the molecules.” And what was happening to the molecules was a war.
A Chokepoint Is Not a Spreadsheet
The Strait of Hormuz is the single most important piece of plumbing in the global oil system. Roughly a fifth of the world’s seaborne crude passes through a channel narrow enough that you can see both shorelines. For weeks this spring, that channel was contested. There was a shooting conflict, a U.S. naval blockade of ships that had called at Iranian ports, and very real questions about whether tankers could transit at all. When the most important valve in the system is half closed, price does what price always does in a shortage. It screams higher. Brent averaged around $107 in May and traded north of that intramonth, after a run that took crude up by roughly half from where it began the year.
Then the geopolitics turned. Mediators announced a memorandum of understanding on June 14, the two presidents signed on June 17, and the naval blockade was lifted. The strait reopened, and the market did the arithmetic on Iranian barrels coming back to a hungry world. The result was the steepest weekly decline in crude in months. By the back half of June, West Texas Intermediate was steadying near $77 and Brent near $80, down roughly 30% from the panic highs in about a month. That is not a financial abstraction. That is the physical reality of supply being un-throttled, and it shows up at the pump within weeks.
Why the New Fed Chair Got Lucky
This is where the monetary story re-enters, and where I think a lot of institutional research is quietly making the right point. The Fed has a new chair and, with him, a deliberate shift toward saying less and guiding markets less. The bigger structural debates, about the size of the balance sheet and how inflation gets measured, are real and will matter for years. But none of that is what moved the near-term inflation outlook. What moved it was crude rolling over.
The fear all spring was “second-round” inflation, the idea that an energy spike seeps into everything that gets made, shipped, or heated and then becomes sticky. With oil sharply lower, that risk recedes on its own. Wall Street analysis that had been bracing for energy to keep bleeding into core prices is now penciling in notable disinflation for the rest of the year. The honest way to say it is that oil did the disinflation work that the central bank would otherwise have had to grind out with blunt and painful tools. The new chair inherited a tailwind he did not create.
The Forecast That Aged in Days
Here is the humbling part, and the reason I keep preaching respect for physical systems. The U.S. government’s own Short-Term Energy Outlook in June modeled Brent averaging around $105 in June and July, explicitly because it assumed the strait would stay mostly closed. Within days, that assumption was overtaken by a signed deal and a price collapse. This is not a knock on the forecasters. It is a reminder that in energy, your headline number is only as good as your assumption about one chokepoint, one pipeline, or one refinery. Change the physical premise and the whole spreadsheet has to be retyped.
So what am I watching now? The memorandum opened a 60-day window to negotiate a durable peace covering nuclear limits, sanctions, and maritime security. That clock is the most important variable in energy right now, more important than any dot plot. Forecasters are already trimming their numbers, with some cutting fourth-quarter Brent targets toward $80. The relief in your inflation data and your fuel bill is real, but it is conditional, and the condition is that a narrow strait stays open. Energy is the economy’s thermostat, and right now someone in the Persian Gulf has a hand on the dial. That is worth far more of your attention than the precise wording of the next policy statement.
Further Reading
- U.S. Energy Information Administration, Short-Term Energy Outlook
- U.S. Bureau of Labor Statistics, Consumer Price Index Summary (May 2026)
- CNBC, “CPI inflation report May 2026: Prices rose 4.2% annually”
- Morningstar, “May CPI Report: Energy-Driven Inflation Is Contained, for Now”
- Congressional Research Service, “Iran Conflict and the Strait of Hormuz: Impacts on Oil, Gas, and Other Commodities”
- TradingEconomics, Brent Crude Oil Price and Historical Data